<div class="conteudo">
    <div id="col_esquerda" style="float: left; width:157px; z-index: 20">
        <div id="div_menu">
            <?php $this->load->view('home/menu'); ?>
        </div>
    </div>
    <div style="float: left; width: 800px; padding-left: 20px; z-index: 10">
        <?php $this->load->view($tela);?>
    </div>
    <div style="clear: both"></div>
</div>